CUATRO CIENEGAS FISHES: RESEARCH REVIEW AND A LOCAL TEST OF DIVERSITY VERSUS HABITAT SIZE
W. L. MINCKLEY Department of. Zoology Arizona State University Tempe, Aizona85287
ABSTRACT
The Cuatro Gidncgas basin, Coahuila, M6xico, supports at least 16 native fish species, 8 of which are cndemic. Research on this fauna is reviewed. Fishes occupy springs, spring-fed rivers, marshes, playa lakes, ephemeral pools, and artificial canals. Number of species per collection is positively correlated with habitat size in stable springs and spring-fed rivers, but not spectacularly so in unstable natural habitats or canals. Distinctive, differcnt asscmblages characterize both stable and fluchrating environments. Ostariophysine and percoid fishes dominate in the former, and cyprinodontoids occupy the latter.
RESUMEN
La cuenca de Cuatro Cidnegas, Coahuila, M6xico, tiene por los menos 16 especies natips dc pcces, de las cualcs 8 eon endtemicas. Se repasan las investigaciones de dicha fauna. Los peces ocup:ln manantiales, rios alimentados por manantialee, pantanos, lagunas playas, charcas elftreras, y canales artificiales. El numero de especies por colecta esd correlacionado positivamente con el tamafro del tfabitat en manantiales estables y rfos alimentqdos por manantiales, pero no tanto en los h6bitats naturales no estables 6 canales. Los arnbientes estables y los que t'ar{an se caracterizan por colectar distintae y diferentee. Los pcces ostariofisos y percoides dominan en los ambientes estables, y los cyprinodontoides ocupan los que nan.
INTRODUCTION.-The intermontane basin of Cuatro collected or observed at 46 localitic on the basic floor wcre Cidnegas, Coahuila, M6xico, supports an unusually diverse compiled for a total of 462 samples as follows: 17 head- fish fauna for a North American desert region. Eight springs (lagunas atd pozos), l9l collections; 10 rivers and families are represcnted, including both Ncarctic (Cyprini- creeks (ribs and, riachuelos), 127; lt baniat (playa) lakes, dac, Ictaluridae, Centrarchidae, Percidae) and Neotropical ci4negas (marshes), and ephemeral pools, 83; and 10 canals, (Characidac, Cyprinodontidae, Poeciliidae, Cichlidae ) com- 6l samples. ponents occupying diverse and abundant aquatic habitats. Headoprings rangc from large ()20 ha, )5 m deep) to Fishes of the basin are relatively well known, yet little small (<10 m2, Minckley, W. L. 1984. Cuatro Cidnegas Fishes: Research Review and a Local Tcst of Diversity Vergus llabitat Size. Jorunel of thc Arizona-Nevada Academy of Science 19:13-21. l4 JOURNAL OF THE ARTZONA-NEVADA ACADEMY OF SCIENCE vol..l9 marshlands. Dircct modifications were evident in 9 of 18 formal names, include Dionda episcopa, Ictalurus lupus, major headsprings listed by Minckley (1969) in 1958-60: Lepomis megalotis, and Micropterus salmoides. Astyanax lagunas Escobeda, Ferrino, Santa Tecla, Tio Candido, Tfo mexicanus, Pylodictis oliuaris, Gambusia rnarshi, Cichla- Quintero, Anteojo, Orosco, and San Marcos. All of these sofira cyanogutattum, and Cichlasoma sp. are undiffcren- plus Poza la Becerra were further canalized by 1981; Con- tiated or little studied. Cichlasoma sp. in the basin is a treras-Balderas (pr€scnt symposium) reporb further on variant defined by morphology of its pharyngeal mill Pozala Becerra. The area has been occupicd by agricultural (LaBounty 1974) that is otherwise distributed in northern man since the 16th Century (Alessio-Robles 1938) so MCxico and southern Texas. The last two forms are com- gome such changcs are old; habitats evidencing carly modi- bined for convenience as C. cf. cyanogutattum for the fications were considered stabilized. Thirty-six of the 191 remainder of this paper. Gambusia marshi, exists as two available samples wcrc from modificd habitats, and are distinct color types (Minckley 1962, Arnold 1966), and analyzed separately. exhibit variations of 2N = 46 and 48 chromosomes (M. K. Habitats wore ranked from I (small) to 10 (large) on a Meyer, pers. comm., 1983) in addition to 2N = 42 as relative basis. Except for playas and ephemeral pools, reported by Campos and Hubbs (1971). It also inhabits which varied in size with time and local conditions, and for the upper Rfo Sa"ao system of Coahuila, into which the habitats that have suffcred direct modifications, I can Cuatro Cidnegas basin now empties, in part as a result of detect fcw changes in discharge of springs and habitats they man's activities. supply over my 25 years of obgewations. Some lagunas A numbcr of works on Cuatro Ci6negas fishes remain have enlarged through foundering, new pozos have similarly wholly or in part unpublished. Included are behavioral appeared, and rivers have slightly altered their courses due studies of Cyprinodon atrorus by Itzkowitz (f967) (see to lateral slumping or accretion of travertines (see Minckley Minckley and Itzkowitz 1967, Itzkowitz and Minckley 1969 for descriptions of processes). The system otherwise 1969), mate-selection investigations of gambusiin fishes appea$ to havc remained stable through time. by Arnold (1966) that included Gambusia marshi nmong Statistical treatments were by least-squares linear otlrers, and behavioral ecology of C. atrorus, C. bifasciatus, rcgression for correlation of habitat eizc (rank) and specics and their hybrids by Arnold (1972) (in small part Minckley diversity (species per collection). Species associations wcre and Arnold 1969). Liu (1969) included Cyprinodon ftom computed as percentage co-occurrence in collections from Cuatro Cidnegas in his comparative studies of behavior in narious habitats. that group (see Liu 1965, Turner and Liu 1977), and Rcsearch in t}e Cuatro Cidnegas basin has been under Stevenson (1975) analyzed karyotypes of Cyprinodon permits to myself and associates from the Mexican Govern- from the basin and elsewhere (Stevenson 1981). Peden ment, and fundcd largely through National Science Founda- (1970) included G. marshi in an evaluation of courtship tion Grants G82461 and,GB6477-X and personal resources. behavior and isolating mechanisms in his studies of the I thank thc many associates who provided assistance in the genus Gambzsra (Peden 1972a-b, 1973). Lysne (1967) field and permittcd usa of unpublished field notes. studied histocompatibility relative to population size and isolation m Xiphophorus gordoni (see also Kallman 1964). RESULTS.-Fishes and Studiee of Fishes of the Basin. Lytle (L972) detailed taxonomic interrelations of the Endemics dominate the basin ichthyofauna of at least 16 Notropis proserpinus group of the middle Rio Grande species: Notropis xanthicara (Minckley and Lytle 1969); region, including N. xanthicara from Cuatro Ci6negas, Cyprinodon atroras and C. bifasciatus (Miller 1968); N. rutilus from Rio Salado and adjacent Rfo San Juan in Lucania interioris (Hubbr and Miller 1965); Gambusia northeastern Mdxico, and others (see also Hubbs and longispinis (Minckley 1962); Xiphophorus gordoni (Millcr Miller 1978). LaBounty (L974) provided a review of and Minckley 1963); Cichlasorna rninckleyi (Komfield and cichlid fistres of northem M6xico, including those from Taylor 1983); and ayet-undescribcd species of Etheostoma the basin. Smith (1982) treated trophic ecology of Cuatro (Minckley 1969, 1978) . Xiphophorus gordoni was rele- Cidnegas cichlids. gated to a subspecies of. X. couchianus by Rosen and Bailey Other papers dealing with divcrse aspects of these (1963), followed by Kallman (1964), and discusscd further fishes include discussions of all or important parts of the by Rosen and Kallman (1969); Roscn (1979) reversed this fauna by Hubbs and Miller (1965), Taylor and Minckley Rosen and Kallman (f969); Rosen (1979) reversed this (1966), Taylor (1966), Minckley (f969, 1978) and Rosen trend, again considering X. gordoni rpecifically distinct. and Kallman (1969). Deacon and Minckley (1974) and I also retain it as a full specics. I remain convinced that Minckley and Brown (1982) included descriptive infor- endemic cichlid fishes of the Cuatro Ci6negas basin in- mation on ecology of Cuatro Ci6negas fishes in their cluded in C. minckleyd comprise a species flock (Taylor treatments of more general subjects. Rivas (1963) and 1966, Taylor and Minckley 1966, LaBounty t974, Minck- Rosen and Bailey (1963) dealt with taxonomic arrange- lcy 1978) rather than a singlc polytypic species (Kornficld ments of fishes of the genus Gambusia, including both and Taylor 1983), which ir to be the subject of another Cuatro Ci€negas species. Minckley (1964) reported on paper. The forms arc here treated as a single taxon to laboratory hybridization experiments involving Garnbusia reduce further confusion in the fiterature. Fishes thought rnarshi and G. affinis. Cokendolpher (1980) included to be differentiated at the cubspecific lcvel, but yet without Cuatro Ci6negas Cyprinodon in his hybridization experi- rssLJE l, 1984 CUATRO CIENEGAS FISHES: RESEARCH REVIEW AND A LOCAL TEST l5 ment8. Thompson (1979) reported on karyotypes of Habitat Size and Fish Divetsity. Natural, stable lagunas, New World cichilids, including Cichlasoma rpp. from the pozos, rivers, and creeks of the Cuatro C6negas basin basin. Kornfield and Koehn (1975), Sage and Selander yielded more spccicc when large, and fewcr species when (1975), Kornfield (198f), Kornfield ct al. (1982), and small (Figs. 1-2). Correlation between diversity and ranked Kornficld and Taylor (1983) included data on morphology size is higher for flowing systems than others (r = 0.79) and relative to diet, plus other ecological interrelatione, in their appcars linear. In unmodified headsprings, smaller habitats studies of Cuatro Ci6negas cichlids. The last authors have fewer fish rpeciee per collection than projected by reviewed mention of these cichlids in other works in their linear regression, and above an arbitrary rank of ca. 3.0 synonymy fot C. minchleyi. Jir{enez et al. (1981) reported (>ZOO mZ1 seems to add no more taxa (x = 6.9![s.d.] 0.33 a new gcnus and species of trematodc from the group (see species/collection, n = 98; Fig. 1) despite a maximum alro Guajardo-Martinez, present symposium). Miller (19 76, available pool of at least 14 spccies. Linear correlation f978, 1981) compared Cuatro Ci6negas Cyprinodon with between diversity and size-rank for unmodified lagunar their congeners, discussed their evolution and zoogeo- (r = 0.63) is not significantly higha (p < 0.05) than that gaphy, and pointcd out problems of survival of the group following canalization (r = 0.60), implying that extinction in gcneral relevant to man's activities in desert areas. relative to decrcasing habitat iizc is not a factor within Deacon et al. (1979), in dealing with status of certain observed limits, even when size reduction is artificial. North American fishes, included a number of Cuatro There ir littlc statistical correlation between ranked Gi6negas species as "endangcred, threatened, or of special sizes of playas, marshes, and ephemeral pools and numberg conccrn," categories applicable to most obligate aquatic of rpecies (Fig, 3), but watcr quality changes select strongly organismr in arid zones of wcatcrn North America. for high salinity and thermal tolerances, thuc forcing reduc- tr o ; U o 6 o o .9 (J o ao. 2 o246810 lncreasing Habitat Size Figrrrc 1. Rcletionfiip bctween ranlcd rize of hcedrpring hebitetr rnd rpccicr 1lcr collcction, Cuatro Cfrncgrr berinn Co.huilr, ItlGxico. Dotr ere for rri. from unmodilicd hrbitrtr; opcn chclcc dcnote vrlucr for hcadrpingr modllicd by canelization; vcrtic.l lincr conncct limitr of varietion. 'l ro+ c CREEKS AND RIVERS 9 P U o r = O.79 lrl- uo o .9 u oc, a o I 1 o246810 Increasing Habitat Size Figrsc 2. Rclrtionrhip betwccn nnlcd rizc of rtrc.mt end ryccier pcr collcction, Guatro Ci€negar barin' Goahuila, MCxico. Symbolr ar in Figrne 1, whcrc appropriatc. t6 JOURNAL OF THE ARIZONA.NEVADA ACADEMY OF SCIENCE vol,. l9 tiong in diversity as ir to be digcussed later. Data poihts for 1979, G. R. Smith 1981, Livingstone et al. 1982, Smith manhes are the highest faunal values in Figure 3, indicating and Millcr 1984). Similar results in natural, stable habitats asrelioration of cevere conditions in those habitate. Canals of the Cuatro Ci6ncgas basin thus are not surprising, even similarly display essentially no correlation between ranked with uee of size-rankcd habitats relative to numbers of habitat rizec and fistr diversity (fig. a). species per collection. DISCUSSION.-Measurcs of habitat size, such as surface The natural laboratory provided by this unique place, arca, have long been recognized as corelatcs of species its stable habitats at onc extreme and markedly unstable diversity (Prcrton 1960, 1962a-b, MacArthur and Wilson habitats at the other, its rclatively small size (<1,500 km2 f967). Larger lakcs have morc figh species t}ran cmaller basin surface area), endorheic drainage, lack of relief (basin ones (Barbour and Brown t974,G. R. Smith 1981). Widcr floor 700 - 760 m elevation), and a relatively large and streams, and river or closed basin systems with greater die- highly endemic ichthyofauna allow one to avoid or readily chargee, volumee, or drainagc areas support more kinds of interpret some factors that often plague analyses of diver- fisheg than narower, srnaller volume, lowerdischarge sity versus habitat size. Certain features do not exist. systems with smaller watershede (Hubbs et al. 1974, Con- Latitudinal and altitudinal variations that result in gradients treras-Balderas 1978, Enans and Noble 1979, Welcommc of diversity (Fischer 1960, Pianka 1966, Emery 1980) PLAYA LAKES, MARSHES, EPHEMERAL POOLS c I o u o o 6 U o .9 u 4 o r = O.22 o. a I II l" 4 6 Increasing Habitat Siie Figurc 3. Rclrtionrhip bctwccn ranled sizc of pbyas, murher, and cphemcral pools and rpecicr pcr collection, Cuatro Ci6ncgrr buil, Coahuilr, M€xioo. Symbolr ae in Figure l, whcre appropriate. I c CANALS I .9 U 0, =o U l' o .9 U c\C) 2 @ -F,Fhd*r2 4 6 I ncneasing Habitat Size Figrnc 4. Relationrhip bctwccn ranlcd rizc of man-nadc canah and rpccieo pcr collcction, Cuatro Ci6negac basin, Coahuila, Itl6xico. Symbolr ar in Ftgurc l, whcre approprlatc. ISSUE I,1984 CUATRO CIENEGAS FISIIES: RESf,ARCH REVIEW AND A LOCAL TEST t7 obviously are absent. However, up- to downstream grad- rheophilic Astyanax rnexicanus and Notropis xanthicara ients in volume, temporal stability, and spatial heterogen- were present in these artificial habitats about a third of eity, all of which influence fishes (Sheldon 1968, Gorman the time (Tablc 1). and Kar 1978, Horwitz 1978, Evans and Noble 1979), are Data presented here reflect in part collecting techni- present and well defined. Climatic influences such as ques and samples available for use from various parts of seasonal temperature and volume fluctuations are essen- the basin. Use of gill and hoop nets set ovemight at all tially absent in large springs and their outflows, but prevail localities certainly would have increased tJre number of in downflow habitats. Barriers to dispersal, although pre- records for lctalurus lupus, arLd possibly Pylodictis oli- sent, are minimal on the basin floor. Most systems or aaris artd Lepornis megalotis. Pylodictis oliaaris, to my rystem types are or have been interconnected in the recent knowledge, has been caught only twice by collectors; past (Minckley 1969, 1978; LaBounty 1974), so species other rccords are visual (underwatcr) sightings or noted richness at a locality could, theoretically, include the entire remains of individual fish caught by anglers. Lack of fauna. A species'absence from a given locale thus con- detailed underwater obscrv-ations definitely reduce num- stitutes aversion to environmental factors rather than bers of records for species just discussed, and for Etheo- physical exclusion. stoma sp. that lives in interstices of complex, travertine Large springs of the Cuato Ci-enegas basin have a dis- stream-bottoms. tinctive and highly predictable fauna consisting of Astya- Incomplete field notes or unavailability of notes and/ nax mexicanus, Notropis xanthicara, Ictalurus lupus, or specimens for collections made by myself and others Cyprinodon bifusciatus, Gambusia tnarshi, Micropterus also influenced the results. Cichlasoma cf. cyanoguttatum sahnoides, and Cichlasoma minckleyr'. Spring-fed rivers definitely occurs in canals in the eastern portion of the support the same fishes, plus Etheostoma sp. (Table 1). basin (LaBounty 1974, Minckley 1978), but ^was not Rheophiles such as N. xanthicara and Dionda episcopa included in data sets utilized. Hybrid Cyprinodon simi' are relatively more abundant in riverline habitats (the larly occupies spring-fed lakes and strcams of the south- latter reaches its greatest relative abundance in canals), westem part of the basin (Arnold 1972, Mincklcy 1978). and, Lepomis megalotis is a more important comPonent Other examples are evident, Future workers dealing with of the fauna in rivers. Xiphophorus gordoni also is rcsffict- this fauna should examine original literaturel rather than ed to headsprings and their immediate outflows; its low referring to generalizations such as in this compilation. frequency of occurrence (Table 1) reflects a limited geo- Graphic presentation of qualitative relations of the fauna graphic distribution in the system (Miller and Minckley by Deacon and Minckley (1974, reproduced by Minckley 1963, Minckley f 978). Cichlasorna cf . cyanoguttatum afso 1978) are, however, borne out by quantitative inforniation is restricted in distribution (LaBounty 1974, Minckley on species numberg versus habitat sizes and types and r978). species' associations. Species with direct access to, but infrequent or absent CONCLUSIONS.-Fishes of largely interconnected, spring- in collections from springs and/or iverc, Pylodictis olfuaris, fed aquatic habitats of the Cuatro Ci6negas basin distribute Cyprinodon atrorus, Lucania interioris, and Gambusia themselves with respect to habitat stability and size. Sprrng- longispinis, arc rare or highly secetive (P. oliaaris) or have heads >200 -2 in surface area and their high-volume out- obvious centers of abundance in other distinctive habitats. flows have a fauna of ostariophysine and percoid fishes Many cyprinodontoids are enhanced by scemingly severe sharply segregated from a cyprinodontoid assemblage in conditions (Miller 1981). Cyprinodon atrorus is remark- ephemeral pools and playa lakes. Exceptions in springs and ably resistant to high temperatures and salinities in desic- spring-fed rivcrs are Cyprinodon bifasciatus and the ubiqui- cating playas and ephemeral pools (Arnold 1972, Deacon tous Gambusia marshi. Only the latter (abundantly) and and Minckley 1974), and apparently "prefers" such places. Cichlasoma minckleyi of the springhead fauna penetrate It occurred alone in 14 of. 64 collections in which it was terminal waters to any degree, the cichlid only as small recorded, and was most commonly associated with the individuals in small numbers. Marshes, if deep and associ- ubiquitous Gambusia rnarshi (Table 1). Lucania interioris ated with springs, provide an intermediate habitat, with a and G. longispinis both occupy weedy, ephemeral habitats mixed fauna including components from both ends of the (Minckley 1962, Hubbs and Miller f965), and co-occuned local spectrum. Marshland ichthyofaunas trend toward there in 64% of recorded collections; G. moshi was typi- cally present with both the last species. Environmental lI opportunity to correct $rme etrors of ommission in factors in variable habitats of the basin select against or t"k" this published maps of species' distributions in the Cuatro Ci€negas are avoided by other than the cyprinodontoids. Cyprino- basin (Minckley 1978). Locations of systems or sites may be found don bifasciatzs is an exception, being restricted to head- in the "Gazeteer of Localities" provided by Minckley (1969): springs, presumably becausc of its stenothermal tendencies Dionda episcopa was recorded from various localities along the La (Miller 1968, Minckley 1978). Angostura Canal prior to its being removed from servict and dried; Canals were dominated by populations of hybrid Notropis xanthicara has been commonly taken from Laguna and Cyprinodon atrorus x C. bifasciatus, Gambusia marshi, Rio Churitt""; Lepomis megalotis is known from Laguna Los Hun- and Cichlasoma minckleyi. As noted above, Dionda epis' didos; and Microptenrs salmo'ides has been repeatedly recorded from copa was most frequently recorded in canals, and the the Tio Candido system. l8 JOURNAL OF THE ARTZONA-NEVADAAC.ADEMY OF SCIENCE vol,.19 Fl s p D s Dr E o p o 6. o 3 !. p a tt, Eege$s$g$gF$$F$$$ EE$E$$$g$E$$$'$$i €o -3. rF I E o E F' a N P tsN OrF@H q qN+O H@ @ o s { {q {Ne{o@ 60 @ { oo A. mexicanus 0 osNo N {@{oN @N@6@UO N a N 9A @6NF { OSO N@ H€OO @ {HO N. xmthicara o @ q oo @oseob 9oo o qq tsHooo po$*No o o N o q N* @{sF @ +o @o Ho o o @o D, episcopa E { o @@ orH@Foo so { H@ qOOOO oooNo o @ N N+ Qe @ o € H@ c' @e o I. lupus ,t o o oo o ll {q oaooo 6@HO o{ o @ o oo o P. o/ll.taris oo o{ooo N It E ONN O { C. atrorus q @ O ai @uN900 { oo ooooo N bifasciatus o o oo ooooo @@o @ C. IF o9 @{ooo o{oooooe Cyprinodon hybs, OEo @o0 N L;nte'io's E @ s oq N*'o { o PN N o 6 C. longis.pinis o € s q@ oo ooooo 00 .| cl N o H@ OOOO o G. marshi q @ {Q o { {6 0000 o € bo X. gordoni otr NO OOO 6 D E s N AO F@ o @ M. salmoides E o q @o o NN @O ! NO ts@ O L megalotis at 600 u {9 0 O Etheostoma zp. IE B o C. minchlefi a(t oo o so 6 a o C, cymoguttatum o o o 6 { o c) E Po F T o{ NNOO s @{@{ oH 6 {NOO o A. mexicarus (t OO HO F€SO oo€@ OFN O €sHoO u N oo *o I @o+@ oo HANO @ N. xanthicua I eo {{ {oo o o{o9 oao s 0 {{ tl os@o l o@ HC N N o@No oo oeo N N D. episcopa o@ oo 90 {ct oNoo ooo o ooo { ! @N oo o o{€@ oo FO L lupus o N FO q{ a oc oo oo o tl oo@o! ooo o o N oa*o o€ P, o6vuis oooo ooo o o o o C. atrcrus o oNoo o{9@ oo C. bifusciatts p, N o900 ooo o EI 0 qFoo { Crprkodon hybs o @ 0 00 0 (!\ oo L interio* oooo ooo F otr GIp q oo o oo G. lottgispirztk o o oooo oo { q G, muslti P oHo @os{ o o O NNO @soN o I X. gordoai ; o OotsO ld. salmoides T OO€O N{ a o{o L. megalotis D o@o Etheostoma sp. o o, or3 x C, minchleyi o @ I C. qmogrttsh.m L rssuE l, 1984 CUATRO CIENEGAS FISHES: RESEARCH REVIEW AND A LOCAL TEST l9 thogc of playas when distant from springs and/or shallow endangcred, threatcned, or of rpccial concern: 1979. and subject to vagaries of direct climatic influence. Spring- Fisheries 4(l)r29a4. heads, although acting as habitat islands, are inhabited by EMERY, A. R. 1980. The basis of fish community struc' a predictablc fauna of uniform sizc and comporition. [n ture: Marine and frcghwatcr comPa,risons. Environ. timc, long isolation should allow proceceer of extinction/ Biol. Fistres 3(f ):33a7. colonization to end in clear LABOUNTY, J. F. 1974. Materials for thc revision of effects of intestinal gas accumulation in a pupfish cichlids from northern Mexico and southern Texas, (genus Cyprinod,on). Trans. Amer. Fish. Soc. 96(2): U.S.A. (Pcrciformes: Cichlidae). Unpubl. Ph.D. Dis- 2 l6-218. sertat., Ariz. St. Univ., Tempe, AZ. and G. A. COLE. 1968. Preliminary limno- LIU, R. K. f 965. Evolution of male courtship behavior logic information on waters of the Cuatro Cienegas of fishes of the American gents Cyprinodon, Amer, basin, Coahuila, Mexico. Southwest. Nat. l3(4):421- Zool. 5 (41 $35-63 6 (abstr.). 48L. . 1969. A comparative behavior of allopatric -, and E. T. ARNOLD. 1969. "Pit digging," a spccies (Teleostci-Cyprinodontida e z Cy prin o d on). Un- behavioral feeding adaptation in pupfishes (genus publ. Ph.D. Diesertat., Univ. Calif., Los Angelcs, Los Cyprinodon). J. Ariz. Acad. Sci. 5(4):254-257. Angeles, CA. andG. L. LYTLE. 1969. Notropis xanthicara, LMNGSTONE, D. A., M. ROWLAND and P. E. BAILEY. a new cyprinid fish from the Cuatro Cienegas basin, 1982. On the size of African riverine faunas. Amer. north-central Mexico. Proc. Biol. Soc. Wash. 82:491- Zool. rl(2\236r-369. 502. LYSNE, J. H. 1967. Histocompatability studies of the and D. E. BROWN. 1982. Part 6. Wetlands. northern platyfish, Xiphophorus gordoni (Poeciliidae). Pp. 222-287, 838-341, + Lit. Cited, In D. E. Brown Unpubl. Ph.D. Dissertat., Ariz. St. Univ., Tempe, AZ. (ed.). Biotic Communities of the American Southwest LYTLE, G. 1972. of. proserpinus L. Revision the Notropis -United States and Mexico. Desert Plants 4(l-4). group, subgenus Cyprinella of. Notropts, from south D. A. HENDRICKSON, and C. E. BOND. Texas and nofihern Mexico (Pisces: Cyprinidae). Un- 1985. Geogaphy of western North American fresh- publ. M. S. Thesis, Ariz. St. Univ., Tempe, AZ. water fishes: description and relations to intraconti- MACARTHUR, R. H. and E. O. WISON. 1967. The nental tectonism. In press, In C. H. Hocutt and E. O. Theory of Island Biography. Princeton Univ. Press, Wiley (eds.). Zoogeography of North American Princeton, NJ. Freshwater Fishes. John Wiley and Sons, N. Y., NY. MILLER, R. R. f968. Two new fishes of the gcnus PEDEN, A. E. 1970. Courtshipbehaviour of Gambusia Cyprinodon from the Cuatro Ci6negar basin, Coahuila, (Poeciliidae), with emphasis on isolating r.nechanisms. Mexico. Occ. Pap. Univ. Mich. Mus. Zool. 659:1-15. Unpubl. Ph.D. Dissertat., Univ. Texas, Austin, TX. 1976. Four new pupfishes of the genus 1972a. Differences in the external genitalia Cyprinodon from Medco. Bull. S. Cdif. Acad. Sci. of female gambusiin fishes. Southwest. Nat. 17(3): 75 (r ):68-75. 265-272. 1978. Composition and derivation of the L972b. The function of gonopodial parts and nativc fish fauna of the Chihuahuan Desert region. behavioral pattern during copulation by Gambusia Pp. 365-381, In R. H. Wauer and D. H. (eds.). (Poeciliidae Riskind ). Canad. J. Zool. 5 0 (7 ) :95 5 -96 8. Trans. Symp. Bicl. Res. Chih. Desert Reg., U. S. and +. 1973. Variation in anal spot expression of Mex., U. S. Nat. Park Serv. Trans. Proc. Ser. 3(1977). gambusiin females and its effect on male courtship. 1981. Coevolution of deserts and pupfishes Copeia f 9 73(2): 250-263. (gews Cyprinodon) in the American Southwest. Pp. PIANKA, E. R. 1966. Latitudinal gradients in species 39-94, In R. J. Naiman and D. L. Soltz (eds.). Fishes diversity: a review of concepts. Amer. Nat. 100(1): in North American Deserts. John Wiley and Sons, 33-46. N.Y., NY. PRESTON, F. W. 1960. Time and space and the variation , and W. L. MINCKLEY. L968. Xiphophorus of spccies. Ecol. 41(4):6 Ll-627. gordoni, a new spccics of platyfish from Coahuila, 1962a. The canonical distribution of com- Mexico. Copeia 1963(3):538.546. monness and rarity: Part 1. Ecol. 43(1):185-215. MINCKLEY, W. L. 1962. Two new species of fishes of f962b. The canonical distribution of com- the genus Gambusia (Poeciliidac) from northeastern monness and rarity: Part II. Ecol.43(3):410431. Mexico, Copeia 1962(2):39 1.396. RMS, L. R. 1963. Subgenera and species groups in thc 1964. Hybridization of two species of mos- peociliid fish genus Gambush Poey. Copeia 1963(2): quitofishes (Gambusia, Poeciliidae) in the laboratory. 83r-347. J. Ariz. Acad. Sci.3(2):87-S9. ROSEN, D. E. 1979. Fishes from the uplands and inter- 1969. Environments of the Bolf5n of Cuatro mountane basins of Guatemala: revisionary studies Ci6negas, Coahuila, Mexico, with special ref€rence to and a comparative geography. Bull. Amer. Mus. Nat. the aquatic biota. Univ. Tex., El Paso, Cei. Ser. 2:1-65. His. 162(5):269-375. 1978. Endemic fishes of the Cuatro Cienegas and R. M. BAILEY. 1963. The poeciliid basin, northem Coahuila, Mexico. Pp. 383404, In fishes (Cyprinodontiformes): thcir rtl-ucture, zoogeo- R. H. Waur and D. Riskind, (eds.). Trans. Symp. Biol. Fraphy, and rystematics. Bull. Amer. Mus. Nat. Hist. Res. Ch*r. Des. Reg., U. S. and Mexico. Trans. Proc. 126(r):1-176,2 ple. U. S. Nat. Park Serv. Scr. 3. and K. D. KALLMAN. 1969. A new fish of and M. ITZKOWrcZ. 1967. Ecology and the genus Xiphophorus from Guatemala, with remarks ISSUE I, l9E4 CUATRO CIENEGAS FISHES: RESEARCH REVIEW AND A LOCAL TEST 2l on thc taxonomy of endemic forms. Amer. Mus. Nov. the Rio Grande basin as inferred from its fish fauna. 237921-29. In press, In C.H. Hocutt and E.O. Wiley (eds.). Zoo' SAGE, R. D. and R. K. SELANDER. 1975. Trophic geography of North American Freshwater Fishes. radiation through polymorphism in cichlid fishes. John Wiley and Sons, N.Y.' NY. Proc. Nat. Acad. Sci. 72(Ll):46694673. STEVENSON, M. M. 1975. A comPaxative chromosome SHELDON, A. L. 1968. Species diversity and longitudinal study of the pupfish gerrus Cyprinodon (Teleostei: succession in stream fishes. Ecol. 49(1): 193-197. Cyprinodontidae). Unpubl. Ph.D. dissertat. Univ' SMITH, D. C. 1982. Trophic ecology of the cichlid Okla., Norman, OK. morphs of Cuatro Cienegas, Mexico. Unpubl. M.S. 1981. Karyomorphology of several species Thesis, Univ. Maine, Orono, ME. of Cyprinodon. Copeia 1981 (2);494498. SMITH. G. R. 1981. Effects of habitat size on species TAYLOR, D. W. f966. A remarkable snail fauna from richness and adult body sizes of desert fishes. Pp. Coahuila, Mexico. Veliger 9zl52'228,1I pls. 125-17L, In R. J. Naiman and D. L. Soltz (eds.). and W. L. MINCKLEY. 1966. New world for Fishes in North American Deserts. John Wiley and biologists. Pac. Disc. 19(1) : 18-22. Sons, N.Y., NY. THOMPSON, K. W. 1979. Cytotaxonomy of.4L species SMITH, M. L. 1981. Late Cenozoic fishes in the warm of Neotropical Cichlidae. Copeia 1979(4):679-69f . deserts of North America: a reinterpretation of desert TURNER, B. J., and R. K. LIU. 1977. Extensive inter- adaptations. Pp. 11-38, In R. J. Naiman and D' L. specific genetic compatibility in the New World killi (2) Soltz (eds.). Fishes in North American Deserts. John fish genus Cy prino don. Copeia L9 7 7 :259'269. Wiley and Sons, N.Y., NY. WELCOMME, R.I. 1979. Fisheries Ecology of Floodplain and R. R. MILLER. 1985. The evolution of Rivers. Longman, London, Engl., and New York, NY. JOURNAL OF THE ARIZONA-NEVADA ACADEMY OF SCIENCE